Re: [PATCH 1/3] cifs.upcall: fix regression with krb5 + creduid

Enzo Matsumiya <[email protected]> writes:

> With 'mount.cifs -o sec=krb5,cruid=XXX' (where XXX > 0), get_uidgid()
> maps XXX to 0, as mount.cifs is running as root.
>
> This makes kerberos lookup for credentials for UID 0, which, if not
> existent, will fail with -ENOKEY.
>
> To fix this, simply ignore UID/GID mapping (get_uidgid() call) when
> arg->uid == 0, as cifs.upcall is already running as root anyway, and
> then kerberos will use 'uid' (which might be 0 or cruid) for lookup.
>
> Fixes: 972c5b5ff95e ("cifs.upcall: remove getpwuid() dependency")
> Reported-by: Paulo Alcantara <[email protected]>
> Signed-off-by: Enzo Matsumiya <[email protected]>
> ---
>  cifs.upcall.c | 30 +++++++++++++++++++++---------
>  1 file changed, 21 insertions(+), 9 deletions(-)

Reviewed-by: Paulo Alcantara (Red Hat) <[email protected]>